Answer:
Explanation:
Considering the atmosphere of the primitive earth to have contained water vapor, carbon dioxide, carbon monoxide, methane, and ammonia and/or nitrogen, then in the presence of an energy source, such as sunlight or lightning, a number of small molecules like hydrogen cyanide, HCN, are formed.
Answer options:
- extraction and observation of DNA
- identification of ribose and deoxyribose
- recognition of RNA as DNA’s messenger
- construction of an accurate DNA model
Answer:
- identification of ribose and deoxyribose
Explanation:
Phoebus Levene was an American biochemist who studied the structure of DNA and RNA. He was able to isolate the sugars (ribose and deoxyribose) from the nucleic acids, which are an important part of their structure.
He also determined how the nucleic acid components combine to form the nucleotides, the basic building blocks of nucleic acids, and how the nucleotides combine in chains to form the polymer.
Answer:
A. Because of base pairing, each strand has all the information to serve as a template for the other strand.
Explanation:
Deoxyribonucleic acid (DNA) is a molecule composed of two antiparallel polynucleotide chains. This double helix serves as a template for its own duplication. DNA templating refers to the process by which a portion of the DNA molecule in a single strand is used as a template to be copied by complementarity base pairing. According to base-pairing rules, Adenine (A) always pairs with Thymine, while Guanine (G) always pairs with Cytosine (C). These nucleotide bases are each linked with their complementary base by hydrogen bonding. When base pairs separate, the hydrogen bond acceptor and donor groups of each strand allow the addition of nucleotides and synthesis of new DNA strands, a process catalyzed by specialized enzymes (DNA polymerases).
Answer:
C. Aldosterone increases sodium reabsorption by increasing the number of Na+-K+ ATPase pumps in the luminal membrane of the proximal tubule.
Explanation:
- Aldosterone hormone is produced by the adrenal gland and mainly carries out its functions in the kidney.Through the aldosterone hormone the body is able to retain more water for the kidney is able to hold more sodium.
- When the plasma sodium levels decrease and the plasma potassium levels increase the production of aldosterone hormone is stimulated for sodium is needed in the .body to maintain the high water levels in the body.
e. There are haploid, diploid, and triploid cells.
